1. Technical Field
The present invention relates to a technology which displays a right eye image and a left eye image to which parallax is mutually applied such that an observer perceives a stereoscopic effect.
2. Related Art
A stereoscopic method using a frame sequential method of alternately displaying a right eye image and a left eye image in a time division manner has been proposed from the related art. In a period during which one of the right eye image and the left eye image is changed to the other, the right eye image and the left eye image are mixed, so that it is difficult for an observer to recognize a definite stereoscopic effect when the observer views the image (crosstalk). In order to solve the above-described problem, for example, JP-A-2009-25436 discloses a technology for causing both the right eye shutter and the left eye shutter of stereoscopic eyeglasses to be in a closed state so that an observer does not view an image in the period during which one of the right eye image and the left eye image is changed to the other (that is, in the period during which the right eye image and the left eye image are mixed).
As shown in FIG. 11, the display period PR of the right eye image and the display period PL of the left eye image are alternately set. Each display period P (PR, PL) is divided into a unit period U1 and a unit period U2. The display image is changed from the left eye image to the right eye image in the unit period U1 of the display period PR and the right eye image is displayed in the unit period U2 which is immediately after the unit period U1, so that the display image is changed from the right eye image to the left eye image in the unit period U1 of the display period PL, and the left eye image is displayed in the unit period U2 which is immediately after the unit period U1. In the unit period U1 of each display period P, control is performed such that both the right eye shutter and the left eye shutter are in the closed state. Accordingly, the mixture of the right eye image and the left eye image is not perceived by the observer.
However, in the foundation of the technology disclosed in JP-A-2009-25436, control is performed such that a period during which the observer can actually view an image is about the half (unit period U2) of each display period P. Accordingly, there is a problem in that it is difficult to sufficiently secure the brightness of a display image.